In recent years, display devices have been developed and widely used in electronic applications such as personal computers, mobile phones, or personal digital assistants. At present, popular choices for display devices include liquid crystal display devices (LCDs), plasma display panels (PDPs), and FEDs. The FEDs have higher contrast ratios, wider viewing angles, higher maximum brightness, lower power consumption, shorter response time, and broader operating temperature ranges when compared to conventional LCDs and PDPs.
The FEDs operate based on emission of electrons in a vacuum and the subsequent impingement of those electrons on a fluorescent layer to emit light, thereby producing a desired image. The electrons are generally emitted from micron-sized or nanometer-sized tips (i.e., electron emitters) in a strong electric field. The electrons are accelerated and then collide with the fluorescent material, thereby emitting the light. The FEDs are thin and lightweight and capable of providing high brightness.
FIG. 5 illustrates a typical FED 40. The FED 40 includes a cathode substrate 41, a cathode 42 disposed on the cathode substrate 41, a transparent anode substrate 45, an anode 44 disposed on the anode substrate 45, and a fluorescent layer 46 formed on the anode 44. The anode 44 is distanced from the cathode 42 via a vacuum interspace 49. The cathode 42 includes a conductive base 47 and a plurality of electron emitters 48 formed thereon. The fluorescent layer 46 includes a plurality of fluorescent units 460.
However, on the one hand, when manufacturing the FED 40, different colored fluorescent powders are coated on selective portions of the anode 44 to form numerous fluorescent units 460, thereby obtaining the fluorescent layer 46. Each fluorescent unit 460 of the fluorescent layer 46 needs to be accurately aligned with each electron emitter 48 of the cathode 42, according to a predetermined alignment approach, to obtain a desired image. Nevertheless, during manufacturing, alignment errors are often incident between the fluorescent units 460 and the electron emitters 48, thus producing image distortion of the FED 40.
On the other hand, referring to FIG. 6, the FED 40 generates a transformation when distorted or folded. In this distorted form, the two substrates 41, 45, the cathode 42, the anode 44, and the fluorescent layer 46 can also generate respective alterations. Due to the interspace 49, after transformation, the electron emitters 48 and the fluorescent layer 46 are misaligned or displaced with respect to each other, accordingly producing an image aberration.
What is needed, therefore, is an FED that can have a relatively accurate and stable alignment between a fluorescent layer and a cathode, even if the FED should become bent or distorted.
What is needed, also, is a method for manufacturing the desired FED.